I started my 140 after a couple of months of not using it (using fresh gasoline), it ran for 3-4 minutes then stalled. I attempted to restart, it cranked over, could hear fuel pump running, getting spark to all 4 plugs, but would not start. Mechanic (here in Panama) says he cannot use computer to diagnose unless it is running. He thinks it is the computer that is defective and it looking for one to borrow to test his theory. Any one have any ideas?